JP3904756B2

JP3904756B2 - Vacuum circuit breaker

Info

Publication number: JP3904756B2
Application number: JP10537599A
Authority: JP
Inventors: 英樹蜂屋; 和行 ▲鶴▼永; 順松崎; 佳延石川; 知美大塚
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1999-04-13
Filing date: 1999-04-13
Publication date: 2007-04-11
Anticipated expiration: 2019-04-13
Also published as: JP2000299041A

Description

【０００１】
【発明の属する技術分野】
この発明は、送配電等に用いられる真空遮断器に関する。
【０００２】
【従来の技術】
従来の真空遮断器の構成を図８に示してあり、真空バルブ１００は真空容器１０１と、この真空容器１０１内に設けられた固定電極１０３および可動電極１０４と、固定電極１０３を支持した固定軸１０５および可動電極１０４を支持した可動軸１０６とで構成されている。
【０００３】
可動軸１０６は真空容器１０１の壁面を摺動自在に貫通してその外部に延出しているとともに、その延出部分に反発リング１０７が取り付けられ、この反発リング１０７に対向して電磁反発コイル１０８が設けられている。また、可動軸１０６にはワイプばね１０９が設けられ、このワイプばね１０９により可動電極１０４が固定電極１０３に所定のワイプ荷重で接触するように保持されている。
【０００４】
そして短絡事故電流が流れたときに、電磁反発コイル１０８をコンデンサ１１０の放電電流により励磁し、この励磁で可動軸１０６に取り付けられた反発リング１０７を反発させて可動電極１０４を固定電極１０３から高速開極させて事故電流を遮断するようになっている。
【０００５】
通常の開閉操作には投入コイル１１１が用いられ、この投入コイル１１１が励磁されている間は可動電極１０４の閉極状態が維持され、励磁の解除に応じて開極ばね１１２の弾性力で可動電極１０４が開極し、この開極状態が開極ばね１１２の弾性力で維持されるようになっている。
【０００６】
【発明が解決しようとする課題】
ところで、電磁反発コイル１０８が励磁されて高速で開極するときには、その反発の衝撃による可動軸１０６の跳ね返りで可動電極１０４が再閉極してしまう恐れがあり、このため従来においては、高速開極したときに瞬時に可動軸１０６を保持して可動電極１０４の再閉極を抑える独立したキャッチ機構１１３が設けられている。
【０００７】
高速開極時における可動軸１０６の衝撃エネルギーは相当大きく、このため従来おいてはリンク機構等の複雑な機構のキャッチ機構１１３を用いて高速開極時に可動軸１０６を保持するようにしており、このためその構成が大掛かりで、設置上のスペースの点、および製作上のコストの点で不利を招く結果となっている。
【０００８】
この発明はこのような点に着目してなされたもので、その目的とするところは、複雑な独立したキャッチ機構を要することなく、通常の開閉操作を行うための開閉操作機構を利用して高速開極時における可動軸の跳ね返りを抑えて的確に可動電極の開極状態を維持することができる真空遮断器を提供することにある。
【０００９】
【課題を解決するための手段】
この発明はこのような目的を達成するために、固定電極に対して接離する可動電極およびこの可動電極を支持した可動軸を備える真空バルブと、この真空バルブの可動電極を電磁反発コイルによる電磁反発力で高速開極させる高速開極機構と、可動部材を永久磁石およびソレノイドを用いて所定のストロークで動作させる開閉操作機構と、この開閉操作機構の可動部材と前記真空バルブの可動軸とを接続体を介して一定範囲の上下移動が可能な状態に接続するとともに、前記固定電極と前記可動電極とにワイプ荷重をかけるワイプばねを備え、且つ前記可動軸の動作をガイドするガイド手段、および前記可動軸の下降時の衝撃を吸収する衝撃吸収手段を有するカップリング機構とを具備し、前記真空バルブの高速開極時には前記可動軸を前記ガイド手段によって前記真空バルブの中心軸上に沿って下降させるとともに、前記ワイプばねを圧縮し、且つ前記衝撃吸収手段に前記可動軸を衝突させて跳ね返りを抑え、これらの動作に合わせて前記開閉操作機構の可動部材を下方に動作させ、この可動部材により前記真空バルブの可動軸を保持して前記可動電極の開極状態を維持し、通常の開閉時には前記開閉操作機構の可動部材を上下に動作させ、このストローク動作で前記可動電極の開閉を行なうようにしたものである。
【００１５】
【発明の実施の形態】
以下、この発明の具体的な実施形態について説明する。
図１に示す実施形態においては、３つの同一構成の真空バルブ１が設けられている。各真空バルブ１は、真空容器２と、この真空容器２内に設けられた固定電極３および可動電極４と、固定電極３を支持した固定軸５および可動電極４を支持した可動軸６とからなり、前記固定電極３と可動電極４とで接点機構７が構成されている。
【００１６】
可動軸６は真空容器２の壁面を摺動自在に貫通してその外部下方に延出し、その延出部分に反発リング８が取り付けられ、この反発リング８に対向して真空容器２の外周に電磁反発コイル９が設けられ、またこの可動軸６の下端部に鍔部材１０が一体的に設けられている。
【００１７】
各真空バルブ１の下方にはその各真空バルブ１に対応してそれぞれカップリング機構１３が設けられている。これらカップリング機構１３は電気絶縁材料からなる接続体１４を有し、これら接続体１４が共通の支持フレーム１５を介して同一のレベルに支持されている。
【００１８】
各接続体１４にはガイド孔１７が形成され、また各可動軸６の下端部に棒状のガイド１８が設けられ、これらガイド１８がその対応する接続体１４のガイド孔１７内に摺動自在に挿入されている。
【００１９】
各可動軸６の鍔部材１０と各接続体１４との間にはそれぞれワイプばね２０が設けられ、これらワイプばね２０により可動軸６が上方に弾性的に付勢され、この付勢力で可動電極４が固定電極３に所定のワイプ荷重で接触するように保持されている。
【００２０】
各接続体１４の上部にはそれぞれほぼコ字状をなす押え部材２１が設けられ、これら押え部材２１の上部壁面に透孔２２が形成され、これら透孔２２内を可動軸６が摺動自在に貫通する状態となっている。そして可動軸６の鍔部材１０が押え部材２１の内側に配置し、この鍔部材１０が押え部材２１に当接することにより可動軸６の接続体１４に対する移動の範囲が規制されるようになっている。すなわち、可動軸６は接続体１４に対して相対的な移動が可能に接続されているが、鍔部材１０と押え部材２１とによりその移動の範囲が一定の範囲に規制されている。
【００２１】
そして、可動電極４が固定電極３に接触する状態のもとでは可動軸６の鍔部材１０と押え部材２１の上部壁面との間に僅かな隙間が確保され、この隙間によりワイプばね２０の弾性力が可動電極４に及んでその可動電極４が固定電極３に所定のワイプ荷重で接触するように保持されている。
【００２２】
接続体１４の上部には可動軸６の下端面と対向し、かつガイド１８を囲むように衝撃吸収手段を構成する緩衝材としての筒状の制振ゴム２３が設けられている。
【００２３】
各接続体１４を支持した支持フレーム１５の下方には開閉操作機構２６が設けられ、この開閉操作機構２６はベース２７と、このベース２７に対して上下動可能に設けられた可動部材２８とを備え、可動部材２８にはベース２７を摺動自在に貫通してその上方に延出する作動軸２９が設けられ、この作動軸２９が前記支持フレーム１５に連結されている。
【００２４】
ベース２７には可動部材２８を上方側に吸引する永久磁石３０が取り付けられ、また可動部材２８にはソレノイド３１が取り付けられている。さらにベース２７と可動部材２８との間には可動部材２８を下方に弾性的に付勢する複数の開極ばね３２が設けられている。
【００２５】
次に、このように構成された真空遮断器の作用について説明する。図１においては、永久磁石３０による磁気吸引力で可動部材２８が所定のレベルの位置に保持され、各真空バルブ１の可動電極４が固定電極３にワイプばね２０により所定のワイプ荷重を保って接触する閉極状態にある。
【００２６】
図２には、短絡事故の発生に伴う高速開極時の動作を順に示してある。図２（Ａ）は真空バルブ１の閉極時の状態であり、この状態から短絡事故等が発生すると、これが制御装置（図示せず）により検出され、この検出で開極用の信号がサイリスタスイッチ３５に出力され、この出力でサイリスタスイッチ３５がオンし、コンデンサ３６から電磁反発コイル９に放電電流が供給され、この電磁反発コイル９が励磁される。
【００２７】
電磁反発コイル９の励磁により、図２（Ｂ）に示すように、反発リング８が瞬間的に反発動作し、この動作で可動軸６が下方に瞬間的に下降し、可動電極４が固定電極３から離間して高速開極が達成され、事故電流が遮断される。
【００２８】
このとき、可動軸６のガイド１８はガイド孔１７に沿って真空バルブ１の中心軸線上に沿って下降する。そして可動軸６はワイプばね２０を圧縮し、制振ゴム２３に衝突し、この制振ゴム２３により可動軸６の下降時の衝撃が吸収される。
【００２９】
一方、開閉操作機構２６のソレノイド３１には、事故発生時に同時に前記制御装置による制御で可動部材２８に永久磁石３０と反発する方向の磁力を生じさせる電流が供給される。
【００３０】
そしてこのソレノイド３１の励磁により、図２（Ｃ）に示すように可動部材２８が下方に押し下げられ、この可動部材２８と一体にカップリング機構１３の接続体１４が下降し、この接続体１４の下降により押え部材２１が可動軸６の鍔部材１０に当接し、この当接で高速開極時の可動軸６の跳ね返りが抑えられ、可動電極４の再閉極が防止される。
【００３１】
さらに連続して図２（Ｄ）に示すように接続体１４が下降し、この下降で押え部材２１を介して可動軸６がさらに下方に引き下げられ、この引き下げで可動電極４が固定電極３からさらに大きく開極する。
【００３２】
この後、ソレノイド３１の励磁が解除される。可動部材２８が所定の位置にまで下降して可動電極４と固定電極３との間に所定のギャップ（開極距離）が形成されたときには、永久磁石３０と可動部材２８との間の距離が一定以上に拡大し、このため可動部材２８に対する永久磁石３０の磁気吸引力が減退し、開極ばね３２の弾性的な付勢力がその吸引力に勝る関係となり、したがってこの時点でソレノイド３１の励磁が解除されても開極ばね３２の付勢力で可動部材２８が所定位置に保持され、可動電極４の開極状態が維持され、その開極のギャップが所定寸法に保持される。
【００３３】
次に、通常の開閉時の動作について説明する。図３には通常の開閉時の動作を順に示してあり、図３（Ａ）においては、永久磁石３０による磁気吸引力で可動部材２８が所定のレベルの位置に保持され、真空バルブ１の可動電極４が固定電極３にワイプばね２０により所定のワイプ荷重で接触する閉極状態にある。
【００３４】
この状態から通常の開極操作が行なわれると、制御装置を介して開閉操作機構２６のソレノイド３１に、可動部材２８に永久磁石３０と反発する方向の磁力を生じさせる電流が供給され、これにより図３（Ｂ）に示すように可動部材２８が下方に押し下げられる。
【００３５】
そしてこの可動部材２８と一体にカップリング機構１３の接続体１４が下降し、この接続体１４の下降により押え部材２１が可動軸６の鍔部材１０に当接する。
【００３６】
さらに連続して図３（Ｃ）に示すように接続体１４が下降し、この下降で押え部材２１を介して可動軸６がさらに下方に引き下げられ、この引き下げで可動電極４が固定電極３から開極する。
【００３７】
そして可動部材２８がさらに下降することにより、図３（Ｄ）に示すように、可動電極４が固定電極３からさらに大きく所定のギャップが生じるまで開極する。
【００３８】
この後、ソレノイド３１解除される。可動部材２８が所定の位置にまで下降して可動電極４と固定電極３との間に所定のギャップが形成されたときには、永久磁石３０と可動部材２８との間の距離が一定以上に拡大し、このため可動部材２８に対する永久磁石３０の磁気吸引力が減退し、開極ばね３２の弾性的な付勢力がその吸引力に勝る関係となり、したがってこの時点でソレノイド３１の励磁が解除されても開極ばね３２の付勢力で可動部材２８が所定位置に保持され、可動電極４が所定のギャップを保って開極する開極状態が維持される。
【００３９】
また、この開極状態から閉極操作が行われたときには、制御装置を介して開閉操作機構２６のソレノイド３１に、可動部材２８に永久磁石３０と吸引しあう方向の磁力を生じさせる電流が供給され、これにより可動部材２８が上方に引き上げられる。
【００４０】
そして可動部材２８の上昇によりこれと一体にカップリング機構１３の接続体１４および可動軸６が上昇し、一定位置まで上昇すると、可動軸６の可動電極４が固定電極３に接触する。
【００４１】
この接触で可動軸６の上昇は停止するが、接続体１４の上昇はさらに続き、これにより押え部材２１が可動軸６の鍔部材１０から離間し、この離間により可動電極４にワイプばね２０の付勢力が作用し、可動電極４が所定のワイプ荷重で固定電極３に接触して所定の閉極状態となる。そしてこの後、ソレノイド３１の励磁が解除され、永久磁石３０による電磁吸引力で可動電極４の閉極状態が維持される。
【００４２】
図４にはこの発明の真空遮断器における高速開極時の特性図を示してある。この図は電磁反発コイル９に５０００Ａ、５００Ｈｚの電流を印加したときの例である。
【００４３】
図４中に破線で示す曲線イは電磁反発コイル電流、実線で示す曲線ロは真空バルブ１の可動電極４のストローク、鎖線で示す曲線ハは開閉操作機構２６の可動部材２８のストロークをそれぞれ表している。
【００４４】
そしてこの特性図に示されているように、通電開始後０．５サイクル（２ｍｓ）で可動電極４のストロークは最大値（１０ｍｍ）に達する。この後、可動電極４のストロークは、電磁反発コイル電流が零となってその電磁反発力が消失した後にも一定時間最大ストロークを維持しているが、やがてそのストロークが減少しかける。
【００４５】
しかし、同時に動作を開始している開閉操作機構２６の可動部材２８のストロークにより最終的にその開閉操作機構２６で設定されたストロークで可動電極４は開極保持される。
【００４６】
この特性図は、電磁反発コイル電流を１サイクル通電とした場合の例であるが、サイリスタスイッチにより通電周波数を１サイクルより多くし（例えば２．５サイクル）、電磁反発力を継続させることで可動軸６の跳ね返りを抑制することも可能である。また、開閉操作機構２６の可動部材２８のストロークを変えることにより、可動電極４の開極安定時のギャップを任意に調整することが可能である。
【００４７】
図５にはこの発明の真空遮断器の回路構成を示してある。この図は１相分の真空バルブ１を駆動する場合の例で、真空バルブ１の固定軸５が主回路電源部４０に接続され、可動軸６が主回路負荷部４１に接続されている。そして真空遮断器の制御装置４２は、高速開極制御ユニット４３と開閉制御ユニット４４とで構成され、これら制御ユニット４３，４４がそれぞれ制御電源４５に接続されている。
【００４８】
高速開極制御ユニット４３は、変圧器４６、整流器４７、電流制限抵抗４８で構成されるコンデンサ充電ユニット４９とサイリスタスイッチ３５とからなり、コンデンサ充電ユニット４９によりコンデンサ３６が常時設定電圧に充電されている。
【００４９】
そして、主回路に短絡等の事故が発生すると、過電流検出器５１が事故電流を検出し、開極信号が高速開極制御ユニット４３、開閉制御ユニット４４に送られる。これにより、高速開極制御ユニット４３のサイリスタスイッチ３５が駆動され、コンデンサ３６に充電されている電圧が放電し、電磁反発コイル９が励磁されるとともに、同時に開閉制御ユニット４４により開閉操作機構２６のソレノイド３１が励磁され、可動部材２８が駆動されて高速開極が行われる。
【００５０】
図５は単相回路の場合であるが、図６に示すように、３相回路の場合には、電磁反発コイル９およびコンデンサ３６を３相独立して接続することにより実現することができる。
【００５１】
さらに図７に示すように構成することも可能であり、この回路構成においては、３相の真空バルブ１を高速開極させるための電磁反発コイル９とコンデンサ３６を３相一括して接続し、１つのサイリスタスイッチ３５で駆動する構成となっている。
【００５２】
この構成の場合には、電磁反発コイル９に流れる分流電流は、独立に接続した場合の分流電流と大きな変化はない。
コンデンサ３６の長期信頼性を考慮すると、オープンモードでの劣化が発生した場合、独立接続においては、劣化相の共振周波数のみが変化するため、劣化相の開極速度が大きく低下し、開極性能に影響する。コンデンサ３６を一括に接続した場合は、正常時と比べ共振周波数は変化するが、３相とも同様に変化するため、開極性能に与える影響を少なくすることができる。
【００５３】
【発明の効果】
以上説明したようにこの発明によれば、従来のような複雑なキャッチ機構を要することなく、通常の開閉操作を行うための開閉操作機構を利用して高速開極時における可動軸の跳ね返りを抑え、可動電極の再閉極を防止してその的確な開極状態を維持することができる。
【図面の簡単な説明】
【図１】この発明の一実施形態に係る真空遮断器の構成を示す構成図。
【図２】その真空遮断器の高速開極時の動作を順に示す説明図。
【図３】その真空遮断器の通常開閉時の動作を順に示す説明図。
【図４】その真空遮断器の特性を示すグラフ図。
【図５】真空遮断器の駆動回路の一例を示す回路構成図。
【図６】真空遮断器の駆動回路の他の例を示す回路構成図。
【図７】真空遮断器の駆動回路のさらに異なる他の例を示す回路構成図。
【図８】従来の真空遮断器の構成を示す構成図。
【符号の説明】
１…真空バルブ
２…真空容器
３…固定電極
４…可動電極
６…可動軸
８…反発リング
９…電磁反発コイル
１３…カップリング機構
１４…接続体
１７…ガイド孔
１８…ガイド
２０…ワイプばね
２１…押え部材
２３…制振ゴム
２６…開閉操作機構
２８…可動部材
３０…永久磁石
３１…ソレノイド
３２…開極ばね
３５…サイリスタスイッチ
３６…コンデンサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum circuit breaker used for power transmission and distribution.
[0002]
[Prior art]
FIG. 8 shows a configuration of a conventional vacuum circuit breaker. A vacuum valve 100 includes a vacuum vessel 101, a fixed electrode 103 and a movable electrode 104 provided in the vacuum vessel 101, and a fixed shaft that supports the fixed electrode 103. 105 and a movable shaft 106 that supports the movable electrode 104.
[0003]
The movable shaft 106 slidably penetrates the wall surface of the vacuum vessel 101 and extends to the outside thereof, and a repulsion ring 107 is attached to the extended portion, and the electromagnetic repulsion coil 108 faces the repulsion ring 107. Is provided. The movable shaft 106 is provided with a wipe spring 109, and the wiper spring 109 holds the movable electrode 104 in contact with the fixed electrode 103 with a predetermined wipe load.
[0004]
When a short circuit accident current flows, the electromagnetic repulsion coil 108 is excited by the discharge current of the capacitor 110, and the repulsion ring 107 attached to the movable shaft 106 is repelled by this excitation to move the movable electrode 104 from the fixed electrode 103 at high speed. The accident current is cut off by opening the pole.
[0005]
A closing coil 111 is used for a normal opening / closing operation, and the closed state of the movable electrode 104 is maintained while the closing coil 111 is excited, and it is movable by the elastic force of the opening spring 112 according to the release of excitation. The electrode 104 is opened, and this opened state is maintained by the elastic force of the opening spring 112.
[0006]
[Problems to be solved by the invention]
By the way, when the electromagnetic repulsion coil 108 is excited and opened at a high speed, the movable electrode 104 may be reclosed by the rebound of the movable shaft 106 due to the impact of the repulsion. An independent catch mechanism 113 is provided that holds the movable shaft 106 instantaneously and suppresses reclosing of the movable electrode 104 when it is poled.
[0007]
The impact energy of the movable shaft 106 at the time of high-speed opening is considerably large. Therefore, conventionally, the movable shaft 106 is held at the time of high-speed opening by using a catch mechanism 113 of a complicated mechanism such as a link mechanism. For this reason, the structure is large-scale, resulting in disadvantages in terms of installation space and manufacturing costs.
[0008]
The present invention has been made paying attention to such points, and the object of the present invention is to use a high-speed opening / closing operation mechanism for performing a normal opening / closing operation without requiring a complicated independent catch mechanism. An object of the present invention is to provide a vacuum circuit breaker capable of accurately maintaining the open state of the movable electrode by suppressing the rebound of the movable shaft at the time of opening.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides a vacuum valve having a movable electrode that contacts and separates from a fixed electrode, a movable shaft that supports the movable electrode, and an electromagnetic repulsion coil that moves the movable electrode of the vacuum valve. a quick opening mechanism for quick opening repulsive force, and opening and closing operation mechanism for operating at a predetermined stroke of the movable member with the permanent magnet and the solenoid, the movable member of the opening and closing operation mechanism and a movable shaft of the vacuum valve A guide means for connecting the fixed body and the movable electrode via a connecting body so as to be movable up and down, and applying a wipe load to the fixed electrode and the movable electrode, and guiding the operation of the movable shaft; ; and a coupling mechanism having a shock absorbing means for absorbing the shock of falling of the movable shaft, said movable shaft at the time of quick opening of the vacuum valve With lowering along the central axis of the vacuum valve by id means, compressing the wiping spring, suppressing bounce and collide with the moveable shaft to the shock absorbing means, the opening and closing operation in accordance with the these operations the movable member of the mechanism is operated downward, maintaining the open state of the movable electrode holding the movable shaft of the vacuum valve by the movable member, operating the movable member of the opening and closing operation mechanism up and down during normal opening and closing it is, in which to perform the opening and closing of the movable electrode in the stroke movement.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described.
In the embodiment shown in FIG. 1, three vacuum valves 1 having the same configuration are provided. Each vacuum valve 1 includes a vacuum vessel 2, a fixed electrode 3 and a movable electrode 4 provided in the vacuum vessel 2, a fixed shaft 5 that supports the fixed electrode 3, and a movable shaft 6 that supports the movable electrode 4. Thus, the fixed electrode 3 and the movable electrode 4 constitute a contact mechanism 7.
[0016]
The movable shaft 6 slidably penetrates the wall surface of the vacuum vessel 2 and extends downwardly from the outside. A repulsion ring 8 is attached to the extended portion, and the repelling ring 8 is opposed to the outer periphery of the vacuum vessel 2. An electromagnetic repulsion coil 9 is provided, and a flange member 10 is integrally provided at the lower end of the movable shaft 6.
[0017]
A coupling mechanism 13 is provided below each vacuum valve 1 corresponding to each vacuum valve 1. These coupling mechanisms 13 have connection bodies 14 made of an electrically insulating material, and these connection bodies 14 are supported at the same level via a common support frame 15.
[0018]
Each connecting body 14 is formed with a guide hole 17, and a rod-shaped guide 18 is provided at the lower end of each movable shaft 6, and these guides 18 are slidable in the corresponding guide hole 17 of the connecting body 14. Has been inserted.
[0019]
A wipe spring 20 is provided between the flange member 10 of each movable shaft 6 and each connection body 14, and the movable shaft 6 is elastically biased upward by these wipe springs 20, and the movable electrode is moved by this biasing force. 4 is held in contact with the fixed electrode 3 with a predetermined wipe load.
[0020]
A presser member 21 having a substantially U-shape is provided at the upper part of each connection body 14, and through holes 22 are formed in the upper wall surface of these presser members 21, and the movable shaft 6 is slidable in these through holes 22. It is in a state of penetrating. Then, the collar member 10 of the movable shaft 6 is disposed inside the presser member 21, and the range of movement of the movable shaft 6 relative to the connection body 14 is regulated by the collar member 10 coming into contact with the presser member 21. Yes. That is, the movable shaft 6 is connected to the connection body 14 so as to be able to move relative to it, but the range of movement is restricted to a certain range by the flange member 10 and the pressing member 21.
[0021]
Under the state where the movable electrode 4 is in contact with the fixed electrode 3, a slight gap is secured between the flange member 10 of the movable shaft 6 and the upper wall surface of the pressing member 21, and the elasticity of the wipe spring 20 is secured by this gap. The force is applied to the movable electrode 4 so that the movable electrode 4 is in contact with the fixed electrode 3 with a predetermined wipe load.
[0022]
A cylindrical damping rubber 23 serving as a shock absorbing material constituting shock absorbing means is provided on the upper part of the connection body 14 so as to face the lower end surface of the movable shaft 6 and surround the guide 18.
[0023]
An opening / closing operation mechanism 26 is provided below the support frame 15 that supports each connection body 14, and the opening / closing operation mechanism 26 includes a base 27 and a movable member 28 that can be moved up and down with respect to the base 27. The movable member 28 is provided with an operating shaft 29 that slidably passes through the base 27 and extends upwardly. The operating shaft 29 is connected to the support frame 15.
[0024]
A permanent magnet 30 that attracts the movable member 28 upward is attached to the base 27, and a solenoid 31 is attached to the movable member 28. Further, a plurality of open springs 32 that elastically urge the movable member 28 downward are provided between the base 27 and the movable member 28.
[0025]
Next, the operation of the vacuum circuit breaker thus configured will be described. In FIG. 1, the movable member 28 is held at a predetermined level by the magnetic attractive force of the permanent magnet 30, and the movable electrode 4 of each vacuum valve 1 maintains a predetermined wipe load on the fixed electrode 3 by the wipe spring 20. Closed contact state.
[0026]
FIG. 2 sequentially shows the operation at the time of high-speed opening accompanying the occurrence of a short circuit accident. FIG. 2 (A) shows a state when the vacuum valve 1 is closed. When a short circuit accident or the like occurs from this state, this is detected by a control device (not shown), and a signal for opening is detected by this detection. The thyristor switch 35 is turned on by this output, the discharge current is supplied from the capacitor 36 to the electromagnetic repulsion coil 9, and the electromagnetic repulsion coil 9 is excited.
[0027]
As shown in FIG. 2 (B), the repulsion ring 8 instantaneously repels by the excitation of the electromagnetic repulsion coil 9, and the movable shaft 6 instantaneously descends downward by this operation, and the movable electrode 4 becomes the fixed electrode. A high speed opening is achieved away from 3 and the fault current is interrupted.
[0028]
At this time, the guide 18 of the movable shaft 6 descends along the guide hole 17 along the central axis of the vacuum valve 1. The movable shaft 6 compresses the wipe spring 20 and collides with the damping rubber 23, and the damping rubber 23 absorbs the impact when the movable shaft 6 is lowered.
[0029]
On the other hand, the solenoid 31 of the opening / closing operation mechanism 26 is supplied with a current that generates a magnetic force in the direction opposite to the permanent magnet 30 on the movable member 28 under the control of the control device at the same time when an accident occurs.
[0030]
2C, the movable member 28 is pushed downward by the excitation of the solenoid 31, and the connection body 14 of the coupling mechanism 13 is lowered integrally with the movable member 28. The presser member 21 comes into contact with the flange member 10 of the movable shaft 6 by descending, and the contact of the movable shaft 6 at the time of high-speed opening is suppressed by this contact, and reclosing of the movable electrode 4 is prevented.
[0031]
Further, as shown in FIG. 2 (D), the connecting body 14 descends, and the movable shaft 6 is further lowered downward through the presser member 21 by this descending, and the movable electrode 4 is moved from the fixed electrode 3 by this lowering. Furthermore, it opens greatly.
[0032]
Thereafter, the excitation of the solenoid 31 is released. When the movable member 28 is lowered to a predetermined position and a predetermined gap (opening distance) is formed between the movable electrode 4 and the fixed electrode 3, the distance between the permanent magnet 30 and the movable member 28 is as follows. Therefore, the magnetic attractive force of the permanent magnet 30 against the movable member 28 is reduced, and the elastic biasing force of the opening spring 32 is superior to the attractive force. Even if is released, the movable member 28 is held at a predetermined position by the biasing force of the opening spring 32, the open state of the movable electrode 4 is maintained, and the opening gap is held at a predetermined dimension.
[0033]
Next, an operation during normal opening and closing will be described. FIG. 3 sequentially shows operations during normal opening and closing. In FIG. 3A, the movable member 28 is held at a predetermined level position by the magnetic attraction force by the permanent magnet 30, and the vacuum valve 1 is movable. The electrode 4 is in a closed state where it contacts the fixed electrode 3 by a wipe spring 20 with a predetermined wipe load.
[0034]
When a normal opening operation is performed from this state, a current that generates a magnetic force in a direction opposite to the permanent magnet 30 is supplied to the movable member 28 to the solenoid 31 of the opening / closing operation mechanism 26 via the control device. As shown in FIG. 3B, the movable member 28 is pushed downward.
[0035]
Then, the connection body 14 of the coupling mechanism 13 is lowered integrally with the movable member 28, and the presser member 21 comes into contact with the flange member 10 of the movable shaft 6 by the lowering of the connection body 14.
[0036]
Further, as shown in FIG. 3C, the connecting body 14 is further lowered, and the movable shaft 6 is further lowered downward through the presser member 21 by this lowering, and the movable electrode 4 is moved from the fixed electrode 3 by this lowering. Open the pole.
[0037]
When the movable member 28 is further lowered, as shown in FIG. 3D, the movable electrode 4 is opened until a predetermined gap is further generated from the fixed electrode 3.
[0038]
Thereafter, the solenoid 31 is released. When the movable member 28 is lowered to a predetermined position and a predetermined gap is formed between the movable electrode 4 and the fixed electrode 3, the distance between the permanent magnet 30 and the movable member 28 increases to a certain level or more. Therefore, the magnetic attractive force of the permanent magnet 30 with respect to the movable member 28 is reduced, and the elastic biasing force of the opening spring 32 is superior to the attractive force. Therefore, even if the excitation of the solenoid 31 is released at this time, The movable member 28 is held at a predetermined position by the biasing force of the opening spring 32, and the open state in which the movable electrode 4 opens with a predetermined gap is maintained.
[0039]
Further, when a closing operation is performed from this open state, a current that generates a magnetic force in a direction in which the movable member 28 attracts the permanent magnet 30 is supplied to the solenoid 31 of the opening / closing operation mechanism 26 via the control device. As a result, the movable member 28 is pulled upward.
[0040]
When the movable member 28 is raised, the connection body 14 and the movable shaft 6 of the coupling mechanism 13 are raised integrally therewith, and when the movable member 28 is raised to a certain position, the movable electrode 4 of the movable shaft 6 comes into contact with the fixed electrode 3.
[0041]
With this contact, the ascent of the movable shaft 6 stops, but the connection body 14 continues to ascend, whereby the presser member 21 is separated from the flange member 10 of the movable shaft 6, and by this separation, the wiper spring 20 is moved to the movable electrode 4. The urging force is applied, and the movable electrode 4 comes into contact with the fixed electrode 3 with a predetermined wipe load to be in a predetermined closed state. Thereafter, the excitation of the solenoid 31 is released, and the closed state of the movable electrode 4 is maintained by the electromagnetic attractive force of the permanent magnet 30.
[0042]
FIG. 4 shows a characteristic diagram at the time of high-speed opening in the vacuum circuit breaker of the present invention. This figure is an example when a current of 5000 A and 500 Hz is applied to the electromagnetic repulsion coil 9.
[0043]
In FIG. 4, a curved line a indicated by a broken line represents an electromagnetic repulsion coil current, a curved line indicated by a solid line represents a stroke of the movable electrode 4 of the vacuum valve 1, and a curved line c indicated by a chain line represents a stroke of the movable member 28 of the opening / closing operation mechanism 26. ing.
[0044]
As shown in this characteristic diagram, the stroke of the movable electrode 4 reaches the maximum value (10 mm) in 0.5 cycle (2 ms) after the start of energization. Thereafter, the stroke of the movable electrode 4 maintains the maximum stroke for a certain period of time after the electromagnetic repulsion coil current becomes zero and the electromagnetic repulsion force disappears, but the stroke is gradually reduced.
[0045]
However, the movable electrode 4 is held open at the stroke finally set by the opening / closing operation mechanism 26 by the stroke of the movable member 28 of the opening / closing operation mechanism 26 which starts the operation at the same time.
[0046]
This characteristic diagram is an example when the electromagnetic repulsion coil current is energized for one cycle, but the energizing frequency is increased from one cycle (for example, 2.5 cycles) by a thyristor switch, and the electromagnetic repulsion force is continued to move. It is also possible to suppress the rebound of the shaft 6. Further, by changing the stroke of the movable member 28 of the opening / closing operation mechanism 26, it is possible to arbitrarily adjust the gap at the time of stable opening of the movable electrode 4.
[0047]
FIG. 5 shows a circuit configuration of the vacuum circuit breaker according to the present invention. This figure shows an example in which the vacuum valve 1 for one phase is driven. The fixed shaft 5 of the vacuum valve 1 is connected to the main circuit power supply unit 40 and the movable shaft 6 is connected to the main circuit load unit 41. The vacuum circuit breaker control device 42 includes a high-speed opening control unit 43 and an open / close control unit 44, which are connected to a control power supply 45.
[0048]
The high-speed opening control unit 43 includes a capacitor charging unit 49 including a transformer 46, a rectifier 47, and a current limiting resistor 48, and a thyristor switch 35. The capacitor charging unit 49 charges the capacitor 36 to a set voltage at all times. Yes.
[0049]
When an accident such as a short circuit occurs in the main circuit, the overcurrent detector 51 detects the accident current, and an opening signal is sent to the high-speed opening control unit 43 and the opening / closing control unit 44. As a result, the thyristor switch 35 of the high-speed opening control unit 43 is driven, the voltage charged in the capacitor 36 is discharged, the electromagnetic repulsion coil 9 is excited, and at the same time, the opening / closing control unit 44 controls the opening / closing operation mechanism 26. The solenoid 31 is excited and the movable member 28 is driven to perform high-speed opening.
[0050]
FIG. 5 shows a single-phase circuit. However, as shown in FIG. 6, a three-phase circuit can be realized by connecting the electromagnetic repulsion coil 9 and the capacitor 36 independently in three phases.
[0051]
Further, a configuration as shown in FIG. 7 is also possible. In this circuit configuration, the electromagnetic repulsion coil 9 and the capacitor 36 for opening the three-phase vacuum valve 1 at high speed are connected together in three phases, It is configured to be driven by one thyristor switch 35.
[0052]
In the case of this configuration, the shunt current flowing through the electromagnetic repulsion coil 9 is not significantly different from the shunt current when connected independently.
Considering the long-term reliability of the capacitor 36, when deterioration in the open mode occurs, only the resonance frequency of the deteriorated phase changes in the independent connection, so that the opening speed of the deteriorated phase greatly decreases, and the opening performance Affects. When the capacitors 36 are connected in a lump, the resonance frequency changes as compared with the normal state, but since the three phases change in the same way, the influence on the opening performance can be reduced.
[0053]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress the bounce of the movable shaft at the time of high-speed opening by using an opening / closing operation mechanism for performing a normal opening / closing operation without requiring a complicated catch mechanism as in the prior art. Therefore, it is possible to prevent re-closing of the movable electrode and to maintain the accurate opening state.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a vacuum circuit breaker according to an embodiment of the present invention.
FIGS. 2A and 2B are explanatory diagrams sequentially illustrating the operation of the vacuum circuit breaker during high-speed opening. FIGS.
FIG. 3 is an explanatory view showing in sequence the operation of the vacuum circuit breaker during normal opening and closing.
FIG. 4 is a graph showing the characteristics of the vacuum circuit breaker.
FIG. 5 is a circuit configuration diagram showing an example of a drive circuit for a vacuum circuit breaker.
FIG. 6 is a circuit configuration diagram showing another example of a drive circuit for a vacuum circuit breaker.
FIG. 7 is a circuit configuration diagram showing still another example of the driving circuit of the vacuum circuit breaker.
FIG. 8 is a configuration diagram showing a configuration of a conventional vacuum circuit breaker.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vacuum valve 2 ... Vacuum container 3 ... Fixed electrode 4 ... Movable electrode 6 ... Movable shaft 8 ... Repulsion ring 9 ... Electromagnetic repulsion coil 13 ... Coupling mechanism 14 ... Connection body 17 ... Guide hole 18 ... Guide 20 ... Wipe spring 21 ... Pressing member 23 ... Damping rubber 26 ... Opening / closing operation mechanism 28 ... Moving member 30 ... Permanent magnet 31 ... Solenoid 32 ... Opening spring 35 ... Thyristor switch 36 ... Condenser

Claims

A vacuum valve comprising a movable electrode that contacts and separates from the fixed electrode and a movable shaft that supports the movable electrode; a high-speed opening mechanism that opens the movable electrode of the vacuum valve at high speed by an electromagnetic repulsion force of an electromagnetic repulsion coil; an opening and closing operation mechanism for operating at a predetermined stroke of the movable member with the permanent magnet and the solenoid, is vertically movable within a predetermined range and movable axis through the connection of the vacuum valve and the movable member of the opening and closing operation mechanism A wiper spring that applies a wipe load to the fixed electrode and the movable electrode, and guides the movement of the movable shaft, and shock absorption that absorbs shock when the movable shaft is lowered A coupling mechanism having means ,
When the vacuum valve is opened at high speed, the movable shaft is lowered along the central axis of the vacuum valve by the guide means, the wipe spring is compressed, and the movable shaft collides with the shock absorbing means. suppressing the rebound, the movable member of the opening and closing operation mechanism in accordance with the these operations are operated downward, maintaining the open state of the movable electrode holding the movable shaft of the vacuum valve by the movable member, conventional vacuum circuit breaker, characterized in that opening and closing of the movable electrode of the movable member up and down is operated, in the stroke motion of the opening and closing operation mechanism for opening and closing.